Various pieces of information are provided through a communication network as webpages displayed in web browsers. Various application programs (hereinafter referred to as “web applications”) that operate on web browsers are also provided. For such webpages and web applications (hereinafter collectively referred to as “web content”), an operation for verifying whether the web content can be normally displayed in web browsers or whether the web content normally operates is performed before the web content is provided.
A plurality of different web browsers are generally used. It is therefore preferable for web content to be displayed and operate in the same manner regardless of a web browser that has read the web content. A cross-browser test, in which web content to be verified is displayed in two different web browsers and display screens of the web browsers are compared with each other, therefore, is often conducted in order to verify web content. In the cross-browser test, images of HyperText Markup Language (HTML) elements included in web content to be verified are obtained in each browser. The images of the HTML elements are then compared between the web browsers in order to determine whether displayed content is the same between the two web browsers.
Depending on web content, however, a dynamic HTML element, whose displayed content changes over time, such as a moving image, might be included. If such a dynamic HTML element is compared between web browsers in the cross-browser test, accurate verification might not be performed since displayed content of an image to be compared differs depending on a timing at which the image is obtained. In order to address this problem, a technique for excluding, from the comparison, an area in which displayed content changes each time a webpage is read in the cross-browser test has been proposed (for example, refer to Shauvik Roy Choudhary, et al., “WebDiff: Automated Identification of Cross-browser Issues in Web Applications”, Proc. of Intl. Conf. on Software Maintenance (ICSM), September 2010).
In the example of the related art, screenshots generated each time a webpage is read in web browsers are compared with each other to detect areas in which displayed content changes, and the detected areas are excluded from areas to be compared between the web browsers.
Depending on how a dynamic HTML element is described, however, two images of the dynamic HTML element obtained at different timings might include the same content. In this case, detection of areas in which the dynamic HTML is displayed can fail in the example of the related art. In view of this situation, it is desirable to improve the accuracy of comparing displayed content between different browsers.